Iron Supplements Can Cause Discomfort for Some

Q:  I have iron-deficiency anemia and my doctor told me to start an iron supplement, but I get very nauseated and constipated from it. I'm otherwise healthy, except for the anemia which is thought to be related to my heavy periods.

Do you have any suggestions on taking iron supplements to make it easier on my stomach?

A:  Iron supplementation can cause nausea, black stools, and constipation for some. If you have problems taking the supplement, sometimes taking a smaller amount helps to make it more tolerable.

There are several forms of iron available with various amounts of iron in them. Ferrous fumarate has the most iron in it and therefore makes patients have the most symptoms from the iron. Ferrous sulfate has the next most, and then ferrous gluconate.

I would recommend trying ferrous gluconate first to see if you can tolerate this, remembering that overall, you are getting less iron and it will likely take you longer to replenish your iron stores than if you took an iron supplement with a higher iron content.

If you still can not tolerate the ferrous gluconate, then I would recommend trying liquid iron that you can adjust in smaller amounts until you tolerate it.

Regardless of the form of iron you take, you should try to take it with vitamin C to absorb as much of it as possible.

If all of this fails, your doctor may recommend intravenous iron, but this is usually used only as a last resort as there can be serious reactions from it.

If you are unable to tolerate the amount of iron that your doctor prescribed, you should discuss with him or her exactly how much you are able to tolerate and if this will be sufficient for you.

Deidre L. Faust, MD, is a Staff Physician (Internal Medicine) at the Medical College of Wisconsin's Plank Road Clinic. Her column appears in the Milwaukee Journal-Sentinel.